L-isomer of atropine with potent anticholinergic activity at muscarinic receptors in smooth muscle, secretory glands, and the CNS. Reduces GI motility and secretions, bladder spasm, and bronchial secretions. Twice as potent as racemic atropine per mg.
At a glance
Class
Anticholinergic / Antispasmodic
Storage
Store at room temperature below 30°C, protect from moisture
Dosing
Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a
Used for GI spasm and urinary urgency/spasm
Safety
Heart rateGI motilityUrine outputPupil size
Interactions
No documented interactions.
FAQs
Frequently asked questions
›What is Hyoscyamine?
Hyoscyamine is a anticholinergic / antispasmodic used in pets. L-isomer of atropine with potent anticholinergic activity at muscarinic receptors in smooth muscle, secretory glands, and the CNS. Reduces GI motility and secretions, bladder spasm, and bronchial secretions. Twice as potent as racemic atropine per mg.
›What is Hyoscyamine used for in pets?
Hyoscyamine is used in veterinary medicine for: Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a; Used for GI spasm and urinary urgency/spasm.
›What is the Hyoscyamine dose for dogs?
For dogs, Hyoscyamine is typically dosed as follows — Used for GI spasm, irritable bowel syndrome, sialorrhea, and bradycardia (oral a: 0.003–0.006 mg/kg PO/SQ q8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Hyoscyamine dose for cats?
For cats, Hyoscyamine is typically dosed as follows — Used for GI spasm and urinary urgency/spasm: 0.003–0.006 mg/kg PO q8h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Hyoscyamine need a prescription?
Yes. Hyoscyamine is a prescription medication and should only be administered under veterinary supervision.
References
References
Textbooks & handbooks
- Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
- Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
- Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
- National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
- The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/
Clinical guidelines & consensus
- Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
- American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.
Journals & peer-reviewed studies
- Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
- Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
- ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control
Regulatory & approvals
- Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/
Databases
- Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet.
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